Hardening apparatus.



APPLICATION FILE MAR. 28, |914.

F.SCHNEMANN. HARDENI'NG APPARATUS.

Patented Apnz?, 1915.

2 SHEETS-SHEET 1.

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WDRNEK F. SCHNEMANN. HARDENING APPARATUS.

APPLICATION FILED MAR.28.19I4.

1,137,293. Patented Apr. Q7, 191.3

v 2 SHEETS-SHEET 2.

- UNITED STATES PATENT GFEICE.

.'RIEDRICH SCHNEMANN, 0F FRIEDRICH-WILHELMSHTTE-ON-THE-SIEG, GERMANY.

HARDENING APPARATUS.

Application filed March 28, 1914.

" b f/N 'clima it muy concern Be it known that I, Fninnnrcn SCHNE- MANX, ay citizen of the German Empire, residing at Friedrich-lVilhelmshiitte-on-the- Sieg, in the Province of Rhenish Prussia, Germany. have invented certain new and useful Improvements in Hardening Apparatus, of which the following is a speci` cation.

This invention relates to a method of hardening blanks or objects of all shapes, particularly calibrated and engraved rollers, straightening rolls and the like, by means of a hardening medium in the form of a powder or gas, and resides in subject ing the object to the action of the hardening medium. while rotating it about its axis. lVhen a hardening medium in the form o `powder is employed, it'is advantageously 20 sprinkled or sprayed upon the object during its rotation.

The novel method is carried into practice in employing a case-hardening furnace provided with. a rotatable tool holder, which is mounted in the cover of the hardening chamber so that it is withdrawn from the furnace when the cover is removed. The novel hardening furnace is also provided with a device for delivering and regulating the hardeningr medium and a pipe for the introduction of the carbonizing gas is carried through the work holder mounted in the furnace cover.

A case hardening furnace for carrying the novel method into practice is illustrated, by way ol' example, in the accompanying drawings, this form of furnace being more particularly adapted for hardening cylindrical and the like objects.

Figure 1 is a vertical longitudinal section of the furnace, and Fig. 2 is a front elevation thereof. Fig. 3 is a. fragmentary section and Fig. 4 a fragmentary plan illustrating the relation of the fuel pipes, the burners, the `combustion chamber and the heating chamber. f

The hardening furnace here illustrated consists broadly of a. casing a inclosing masonry b in the interior of which the inutile c serving for the reception of the objects to be hardened is arranged in such a manner that it is surrounded by a passage d in lwhich the combustion of the heating gases conducted through the pipe f and suitable communicating burners f directed into said passage takes place. The products of Specification of Letters Patent.

Patented Apr. 27, 1915.

seriai No. 827,868.

combustion are removed therefrom through a suitable outlet pipe .15. The object or blank ,r/,to he hardened is placed in the maille. being carried by a work holder constituted by a spindle or trunnion z' rotatably mounted in the cover l). and adapted to be rotated by means of worm gear 7c by a hand wheel I. Internally the work holder is bored for the reception of tubes m, 7i, arranged one inside the other, the inner tube In. serving for the introduction of a gas into the interior of the muiile,while the outer tube m, which is open at the end, serves, in conjunction with the said bore, for cooling the work holder. the hardening process and particularly the temperature. of the work, the muflle isprovided with an inspection aperture rc whii is adapted to be closed. The cover It with the work holder i' is adapted to travel on the rails p on rollers o so that the work can readily be introduced into the muiile and removed therefrom. A pipe g opening from above into the muHle, is provided for the introduction of the hardening powder; in a lateral socket of this pipe a conveyer Worm rotatable by a crank s is arranged and serves to supply the hardening powder contained in the hopper t gradually through thc pipe g on to the work and into the inutile. Above the front opening of the muflle a sliding door u is guided in the vertical direction. This door is suspended upon the cable lw carried over the rollers o and when the work has been removed it can be lowered to close the mufle.

The apparatus for carrying out the novel hardening process operates in the following rnannerz-rl`he work to be hardened, which is preliminarily heated outside the apparatus to a given temperature, is placed upon the trunnion of the work holder upon which it is introduced into the mufile that has preY` viously been brought to a given temperature by external heating. l/Vhen the necessary temperature has been attained, which can be observed from the exterior through the inspection aperture m, the hardening powder is gradually sprinkled on to the work g by rotating the crank s, the work being preferably rotated at the same time by turning the hand wheel l, so that the hardening powder is distributed uniformly on all'sid'es. These two movements may be given independently of each other or in dependence upon each other, as desired. Simultaneously the gases To permit of observing cansbe introduced into the interior of the mullie through the pipe n inside the Work holder i; these gases should not be com bustible but as they contain a large percentage of carbon, they assist the hardening together with the gases arising from the hardening powder. For this reason no special air admission oricc is provided. The process of combustion and the temperature of the work can he exactly followed throu h the inspection aperture so that by modi' ing the supply of gas and hardening medium, the hardening process can be regulated in tlm manne" necessary for obtaining the desired degree of hardness.

Claims l. ln a case hardening furnace: a support to which the article to be hardened may be attached and provided with a duct through which a gaseous medium may be introduced about the said article and a second duct about said first duct through which a cooling medium may be introduced to cool the said support for the article, and means to.

rotate said support.

2. In a case hardening furnace: a suitable metile, means to close the same, a support carried by said closing means and to which the article to be hardened may be attached, means to rotate said support, and means to supply a hardening medium about said an.

ticle.

3. ln a case hardening furnace: a suitable mutile, means to close the' same, a sup rt carried by said closing means and to w ich the article to be hardened may' be attached, said support being provided with a. duct through which a aseous medium ma be introduced about tie said article, an means to rotate said support. I

4. In a case-hardening furnace: a suitable muflie, means to close the same, a support carried by said closing means and to which thearticle to be hardened may be attached. means to rotate said support, means to sprinkle a pulverulent hardening medium upon said article, and moans to regulate the supply of hardening medium during the hardening operation.

5. ln a case hardening furnace: a suitable muffle, a movable cover to close the same, a support carried by said cover and to which the article to he hardened may be attached, said support having n. duct therethrough through which a gaseous medium may be introduced about the said article, means to rotate said support, and a spiral conveyer to sprinkle a. pulverulcnt hardening medium upon said article.

In testimony whereof I- have hereunto signed my name to this specication in the prese-nce of two subscrilnngzwjtnesses.

FRIEDRICH SCHGNEMANN.

4Vv'tnesses i RUNor-v. STADLER, Louis VANDORN. 

